GPS北斗双模技术应用开发研究—数据结构扩展

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GPS北斗双模技术应用开发研究—数据结构扩展

edsam 2014-12-09 18:23:45 浏览369
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 GPS北斗双模技术应用开发研究—数据结构扩展

 

          还是从gps.h头文件入手,首先 GpsSvStatus结构体需要改造,GpsSvStatus当时设计的时候是考虑存储gps卫星信息的,但是我们现在是要存储双模的数据,因此我们需要扩展这个数据结构,那怎么扩展呢?

  当然要代价小一点,不能完全推倒重来的,笔者想到的就是增加一个北斗卫星数量的变量,以及北斗的epemeris、almanac、还有一个定位的mask,以前数据结构里面的成员全部用着gps存储,这样就相互独立了,但是sv_list笔者就偷懒共用了,只是把这个数组扩大一倍,后半部分存储北斗卫星信息,这样的话第一步就算完成了。基本如下:

 /** Maximum number of SVs for gps_sv_status_callback(). */
-#define GPS_MAX_SVS 32
+#define GPS_MAX_SVS 64
 
 /** Requested operational mode for GPS operation. */
 typedef uint32_t GpsPositionMode;
@@ -306,6 +306,25 @@ typedef struct {
      * were used for computing the most recent position fix.
      */
     uint32_t    used_in_fix_mask;
+
+       /** Number of  bd SVs currently visible. */
+    int         bd_num_svs;            
+
+    /** Represents a bit mask indicating which SVs
+     * have ephemeris data.
+     */
+    uint32_t    bd_ephemeris_mask;
+
+    /** Represents a bit mask indicating which SVs
+     * have almanac data.
+     */
+    uint32_t    bd_almanac_mask;
+
+    /**
+     * Represents a bit mask indicating which SVs
+     * were used for computing the most recent position fix.
+     */
+    uint32_t    bd_used_in_fix_mask;   
 } GpsSvStatus;

        解析本身的难度不大,依葫芦画瓢罢了,都是固定的。那就看一下GSV怎么解析的吧!如下:

if ( !memcmp(tok.p, "GSV", 3) ) {
        int noSatellites;
        Token  satellite_to_view;

		is_beidou = !memcmp(ptr, "BD", 2); 
        satellite_to_view = nmea_tokenizer_get(tzer, 3);
        noSatellites = str2int(satellite_to_view.p, satellite_to_view.end);
        ALOGV(">>>is_beidou (%d) GSV satellite_to_view=%d", is_beidou, noSatellites);
        if (noSatellites > 0 ) { //tmp  
            int sentence, totalSentences, curr, i, bd_cur;
            Token  num_of_msg;
            Token  no;
            num_of_msg    = nmea_tokenizer_get(tzer, 1);
            no            = nmea_tokenizer_get(tzer, 2);

            sentence = str2int(no.p, no.end);
            totalSentences = str2int(num_of_msg.p, num_of_msg.end);
            D(">>>gsv_index=%d,gsv_total=%d",sentence, totalSentences);

            if (sentence == 1 && !is_beidou) {
                r->sv_status.num_svs = 0;
                r->sv_status.ephemeris_mask = 0ul;
                r->sv_status.almanac_mask = 0ul;
                r->sv_status.bd_num_svs= 0;
                r->sv_status.bd_ephemeris_mask= 0ul;
                r->sv_status.bd_almanac_mask= 0ul;
			}
			
            curr = r->sv_status.num_svs;
			bd_cur = r->sv_status.bd_num_svs + 32;
            i = 0;

            while (i < 4 && (r->sv_status.num_svs < noSatellites ||
				               (is_beidou && r->sv_status.bd_num_svs < noSatellites))) {
                int prn;
                Token    tok_prn = nmea_tokenizer_get(tzer, i * 4 + 4);
                Token    tok_elevation = nmea_tokenizer_get(tzer, i * 4 + 5);
                Token    tok_azimuth = nmea_tokenizer_get(tzer, i * 4 + 6);
                Token    tok_snr = nmea_tokenizer_get(tzer, i * 4 + 7);

                prn = str2int(tok_prn.p, tok_prn.end);
                if (prn <= 0) { i += 1; continue; }

				
                if(is_beidou) {
				    if(prn > 400)
					    prn -= 400;//M8 BD base 400

					r->sv_status.sv_list[bd_cur].prn = prn;
					
					r->sv_status.sv_list[bd_cur].elevation = str2float(tok_elevation.p, tok_elevation.end);
					r->sv_status.sv_list[bd_cur].azimuth = str2float(tok_azimuth.p, tok_azimuth.end);
					r->sv_status.sv_list[bd_cur].snr = str2float(tok_snr.p, tok_snr.end);
					r->sv_status.bd_ephemeris_mask|= (1ul << (prn-1));
					r->sv_status.bd_almanac_mask|= (1ul << (prn-1));
					
					r->sv_status.bd_num_svs+= 1;// bd num
	                r->sv_status.num_svs += 1;//total num
	                if(r->sv_status.sv_list[bd_cur].snr > 0)
                       ALOGV("**bd_cur=%d num_svs:%d prn:%d snr=%f\n", bd_cur, r->sv_status.num_svs,
                                r->sv_status.sv_list[bd_cur].prn,r->sv_status.sv_list[bd_cur].snr);
                    bd_cur += 1;

                } else {
	                r->sv_status.sv_list[curr].prn = prn;

	                r->sv_status.sv_list[curr].elevation = str2float(tok_elevation.p, tok_elevation.end);
	                r->sv_status.sv_list[curr].azimuth = str2float(tok_azimuth.p, tok_azimuth.end);
	                r->sv_status.sv_list[curr].snr = str2float(tok_snr.p, tok_snr.end);
	                r->sv_status.ephemeris_mask |= (1ul << (prn-1));
	                r->sv_status.almanac_mask |= (1ul << (prn-1));

	                r->sv_status.num_svs += 1;
				
				if(r->sv_status.sv_list[curr].snr > 0)
                    ALOGV("##curr=%d num_svs:%d prn:%d snr=%f\n", curr, r->sv_status.num_svs,
                                r->sv_status.sv_list[curr].prn,r->sv_status.sv_list[curr].snr);
                    curr += 1;
                }
				
                i += 1;
            }
     
        其他的GGA这些双模不双模都是一样的。下面我们看看在JNI里面,android_location_GpsLocationProvider_read_sv_status上报的各个卫星的情况的,显示他的接口也是需要改造的,要扩展,如下:

@@ -465,17 +465,34 @@ static jint android_location_GpsLocationProvider_read_sv_status(JNIEnv* env, job
     jfloat* elev = env->GetFloatArrayElements(elevArray, 0);
     jfloat* azim = env->GetFloatArrayElements(azumArray, 0);
     jint* mask = env->GetIntArrayElements(maskArray, 0);
+       int i, j;
 
     int num_svs = sGpsSvStatus.num_svs;
-    for (int i = 0; i < num_svs; i++) {
+    int bd_num_svs = sGpsSvStatus.bd_num_svs;
+
+       //gps info
+    for (i = 0; i < (num_svs - bd_num_svs); i++) {
         prns[i] = sGpsSvStatus.sv_list[i].prn;
         snrs[i] = sGpsSvStatus.sv_list[i].snr;
         elev[i] = sGpsSvStatus.sv_list[i].elevation;
         azim[i] = sGpsSvStatus.sv_list[i].azimuth;
     }
+
+    //bd info
+    for (j = 0; j < bd_num_svs; j++) {
+        prns[i+j] = sGpsSvStatus.sv_list[32+j].prn;
+        snrs[i+j] = sGpsSvStatus.sv_list[32+j].snr;
+        elev[i+j] = sGpsSvStatus.sv_list[32+j].elevation;
+        azim[i+j] = sGpsSvStatus.sv_list[32+j].azimuth;
+    }
+       
     mask[0] = sGpsSvStatus.ephemeris_mask;
     mask[1] = sGpsSvStatus.almanac_mask;
     mask[2] = sGpsSvStatus.used_in_fix_mask;
+    mask[3] = bd_num_svs;      
+    mask[4] = sGpsSvStatus.bd_ephemeris_mask;
+    mask[5] = sGpsSvStatus.bd_almanac_mask;
+    mask[6] = sGpsSvStatus.bd_used_in_fix_mask;
    这个JNI接口直接就得了gps的location provider了,同样要扩展

@@ -1285,7 +1285,9 @@ public class GpsLocationProvider implements LocationProviderInterface {
                 try {
                     listener.mListener.onSvStatusChanged(svCount, mSvs, mSnrs,
                             mSvElevations, mSvAzimuths, mSvMasks[EPHEMERIS_MASK],
-                            mSvMasks[ALMANAC_MASK], mSvMasks[USED_FOR_FIX_MASK]);
+                            mSvMasks[ALMANAC_MASK], mSvMasks[USED_FOR_FIX_MASK],
+                            mSvMasks[BD_SVS_NUM], mSvMasks[BD_EPHEMERIS_MASK],
+                            mSvMasks[BD_ALMANAC_MASK],mSvMasks[BD_USED_FOR_FIX_MASK]);
                 } catch (RemoteException e) {
                     Log.w(TAG, "RemoteException in reportSvInfo");
                     mListeners.remove(listener);
@@ -1296,22 +1298,33 @@ public class GpsLocationProvider implements LocationProviderInterface {
         }
 
         if (VERBOSE) {
-            Log.v(TAG, "SV count: " + svCount +
+            Log.d(TAG, "SV count: " + svCount +
                     " ephemerisMask: " + Integer.toHexString(mSvMasks[EPHEMERIS_MASK]) +
                     " almanacMask: " + Integer.toHexString(mSvMasks[ALMANAC_MASK]));
             for (int i = 0; i < svCount; i++) {
-                Log.v(TAG, "sv: " + mSvs[i] +
+                               if(i < (svCount - mSvMasks[BD_SVS_NUM])){
+                Log.d(TAG, "sv: " + mSvs[i] +
                         " snr: " + mSnrs[i]/10 +
                         " elev: " + mSvElevations[i] +
                         " azimuth: " + mSvAzimuths[i] +
                         ((mSvMasks[EPHEMERIS_MASK] & (1 << (mSvs[i] - 1))) == 0 ? "  " : " E") +
                         ((mSvMasks[ALMANAC_MASK] & (1 << (mSvs[i] - 1))) == 0 ? "  " : " A") +
                         ((mSvMasks[USED_FOR_FIX_MASK] & (1 << (mSvs[i] - 1))) == 0 ? "" : "U"));
+            } else {
+
+                           Log.d(TAG, "BD sv: " + mSvs[i] +
+                                       " BD snr: " + mSnrs[i]/10 +
+                                       " BD elev: " + mSvElevations[i] +
+                                       " BD azimuth: " + mSvAzimuths[i] +
+                                       ((mSvMasks[BD_EPHEMERIS_MASK] & (1 << (mSvs[i] - 1))) == 0 ? "  " : " E") +
+                                       ((mSvMasks[BD_ALMANAC_MASK] & (1 << (mSvs[i] - 1))) == 0 ? "  " : " A") +
+                                       ((mSvMasks[BD_USED_FOR_FIX_MASK] & (1 << (mSvs[i] - 1))) == 0 ? "" : "U"));
+               }
             }
         }
 
         // return number of sets used in fix instead of total
-        updateStatus(mStatus, Integer.bitCount(mSvMasks[USED_FOR_FIX_MASK]));
+        updateStatus(mStatus, (Integer.bitCount(mSvMasks[USED_FOR_FIX_MASK] + Integer.bitCount(mSvMasks[BD_USED_FOR_FIX_MASK]))));
 
         if (mNavigating && mStatus == LocationProvider.AVAILABLE && mLastFixTime > 0 &&
             System.currentTimeMillis() - mLastFixTime > RECENT_FIX_TIMEOUT) {
@@ -1895,17 +1908,21 @@ public class GpsLocationProvider implements LocationProviderInterface {
     }
 
     // for GPS SV statistics
-    private static final int MAX_SVS = 32;
+    private static final int MAX_SVS = 64;
     private static final int EPHEMERIS_MASK = 0;
     private static final int ALMANAC_MASK = 1;
     private static final int USED_FOR_FIX_MASK = 2;
+    private static final int BD_SVS_NUM = 3;
+    private static final int BD_EPHEMERIS_MASK = 4;
+    private static final int BD_ALMANAC_MASK = 5;
+    private static final int BD_USED_FOR_FIX_MASK = 6;
 
     // preallocated arrays, to avoid memory allocation in reportStatus()
     private int mSvs[] = new int[MAX_SVS];
     private float mSnrs[] = new float[MAX_SVS];
     private float mSvElevations[] = new float[MAX_SVS];
     private float mSvAzimuths[] = new float[MAX_SVS];
-    private int mSvMasks[] = new int[3];
+    private int mSvMasks[] = new int[7];
     private int mSvCount;
     // preallocated to avoid memory allocation in reportNmea()
     private byte[] mNmeaBuffer = new byte[120];

   这就已经都java部分了,完成了大半了,后面再讲后半段的处理,也还有很多的道道在里面。


 

   

 

 

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